Process and apparatus for cracking and treating hydrocarbons



Patented Nov. 17, 1931 UNITED STATES 'PATENT 0,lili-*ica-fV A Homan T. DARLINGTON, or wEs'r CHESTER, PENNSYLVANIAfASSIfGNORfTo B. scnusrna, 'rausrnaor fromm, ILLINOIS;H

PROCESS AND APPAaA'rus Fon caAcxINe AND 'mirarme HYDBOCARBON'S Original application ledApril 25, E27, Serial No. 186,463. Divided and this application led Februari' 5,

1931. Serial No. 513,731. u `v 1^ *f I,

This application is a division of my application, Serial No. 186,463, filed April 2.5, 1927.

An object of this invention is to provide a process and apparatus for more completely and efficiently cracking into low-boiling point hydrocarbons, and otherwise making marketable products out of petroleum hydrocarbons of relatively high-boiling points.

In carrying out my invention, I take an oil, for instance, crude oil, after the gasoline has been removed by topping, or gas oil, and introduce and subject said oil in a pressure cracking still to a hundred or more pounds of pressure per square inch and to a temperature of TO0CJ F. or more, whereby gasoline, kerosene, and other heavier distillates volatilize or form and then volatilize. The vaporsI are passed into a cooling chamber, for instance, a dephlegmator, which condenses 9 as an intermediate product distillates heavier than gasoline. This intermediate product I pump through a separate continuous tube still using a higher pressure, and, if desired, a higher temperature than Was used in the first cracking, and the intermediate product is thereby altered into gasoline and into substantially heavier and higher boiling point products which I call manufactured charging stock.

My invention comprises treating under cracking conditions of heat and superatmospheric pressure an oil of comparatively high boiling point, for instance, crude or gas oil, or other cracking stock for the production of gasoline and of other volatile products by cracking and the separation and Withdrawal from the first or lower pressure part of the system of a portion of the residue of heavier hydrocarbons to mix with the herein referred to intermediate product, which is cracked at a. higher pressure than used in the first part ofthe system. It also comprises the production of a manufactured charging stock from the cracking mixture, and forcing they .remainder or all of the manufactured charging stock to the first or lower pressure part of the cracking system.

The invention will be more fully understood by reference to the accompanying drawing which shows idiagrammatically appa-I ratus for carrying out the invention.

In the draW1ng,-a coil or other like apparatus V1k of 'approved type operating under fj require indicating by number, particularly as their operation is sosimpleas to befreadily understood Without explanation. The element 2 is a reaction or treatment chamber of approved type in communication by means of a fpipe 10 and pum 10B with thel heatingcoil 1 rom which coil c arging stock treated ltherein passes through the pipe l0b to the reaction chamber?, forv further cracking and vaporization. ,A f

The element 3 is a dephlegmator cooled by pipe line,26,`an'd may be any approved means of cooling and Wholly or partly separating intermediate products, as already defined;V

4 is a condenser of 'any approved type, and 5 is a gasoline storage tank; `6 is a high pressure still,'or other like apparatusadapted for treating at higher temperature and pressure than that applied in the still l; 7 is a secondary reaction `chamber adaptedto Areceive oil heated by the high pressure still 6; 8 is a storage tank for a product, and 9 is a means of separating Water from the intermediate product removed from the dephlegmator 3; The functions ofthe various pipe lines shown are self-evident, the directions of flow of the oil therethrough, being indicated by the arrows. They arecontrolled by valves, as shown.

In practice, charging stock is continuously or intermittently added to the low pressure still l by means ofthe pump'glOa which receives this stock from a suitable source of supply through the pipell9, there treated under conditions of temperature and superatmospherici pressure conducive to cracking,- and Withdrawn at cracking temperatureand pressure through the pipe 10b into the reacfined intermediate products and gasoline are removed in vapor form through the pipe l1 to the dephlegmator 3. Gasoline passes thence, as a vapor, through the valve control pipe line 15 into a condenser 4, and is transferred through the pipe line 18 and stored in the tank 5. ,v

Sufficient charging stock is introduced either continuously or intermittently, through pipe 1911 to maintain hydrocarbon in a liquid form in the reaction chamber at a predetermined level in the upper part of that chamber, leaving, however, space for the vapors that separate out of the liquid to accumulate.

From the reaction chamber 2 a portion of the non-volatilized oil may be removed by valve-controlled pipe line as 10, located as convenience dictates, and `again forced by a pump as 10, or other suitable means, to the coil 1 forreheatinr and further treatment and/or a portion of said non-volatilized oil may be withdrawnentirely from the system through pipe 30, or it may be withdrawn and carried through a convenient valve-controlled pipe line 20 and deliveredto a line 14, carrying intermediate product from thedephlegmator 3 and be intermingled with such intermediate product.

The intermediate product is removed from the dephlegmator 3 through pipes 13 and 16, either selectively-the v heavier fractions through the pipe line 16, the valve 16l being open, and the lighter fractions through the pipe line 13--or non-selectively, and, either with or without commingling with heavier oil withdrawn from `the reaction lchamber 2, through the pipe 20, is carried through the pipe line 14, forced by a pump 14, or other suitable means of propulsion into and throu h the high pressure still 6, and therev heated by means of the burner 6, It then passes through valve-controlled line 6b to the secondary reaction chamber 7, where cracking continues, the vapors passing over into the dephlegmator 3 through pipe 12.

j A part of the intermediate product passing through the high pressure still 6 may, if desired, be passed through the valve-controlled pipe line 19 directly to the low pressure still 1 as intermediately manufacturedstock. When assed into chamber 7 for treatment, it may be made into a final product, which in turn can be transferred byl the valve-controlled pipe line 17 to the stock tank 8, and withdrawn by line 31 or 29, or the residue v from the reaction chamber 7 may be returned through the pipe -line 24 to the main pipe line 19 and thence passed through the coil 1. If desired, intermediate reflux products from the dephlegmator 3 may be withdrawn through the valve-controlled outlet 23, and they-may be passed through the water separator 9.

Thus it will be seen, as a preferred method of operation, I have provided means whereby `kerosene and gas oil forming the bulk of the reflux .or intermediate stock than is the low pressure still 1 and reaction chamber 2. The residuum remaining in the reaction chamber 7 is a much heavier stock than that received bythe still 6. This residuum will not crack well in the high pressure still 6, but I have discovered that it does crack Well in the low pressure still 1. I, therefore, return this manufactured charging stock to the still 1, and by pipe line 20 mix oil from still 1 with reflux from line 14 passing to the higher pressure still 6.

I have shown pressure gauges 32, 32", 32, 32d, 32e for indicating pressures; 33a, 33", 33c are means of indicating liquid levels, and 34, 34h, 34c, 34d are means of determining temperatures.

While I have shown and described but a few embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

1. Apparatus for cracking hydrocarbon oil comprising a low-pressure heating coil, a reaction chamber in communication therewith, a fractionating condenser connected to and adapted to condense vapors from said reaction chamber, a high-pressure heating coil n `connected to and adapted to receive the heavier hydrocarbon fractions from said condenser, a secondary reaction chamber in communication with heating coil adapted to deliver vapors to a vapor condensing means, and means for passing portions of the unvaporized oil from the secondary reaction chamber to the lowpressure heating coil.

2. Apparatus for treating hydrocarbon oil comprising a low-pressure heating coil, a reaction chamber in communication therewith, a fractional condenser adapted to condense vapors from said reaction chamber, a highpressure heating coil adapted to receive the heavier hydrocarbon fractions from said condenser, a secondary reaction chamber in communication with said high-pressure heating coil adapted to deliver vapors to a vapor f condensing means, means for passing por tions of the unvaporized oil from the secondary reaction chamber to the low-pressure heating coil, means for withdrawing gasoline, means for withdrawing an unvaporized said high-pressure 1 product, and a means for supplying fresh V oils to make gasoline comprising low-pres-A sure means for heating and cracking said oils, a fractioiiating condenser receiving vapors from said heating means, means for condensing vapors of gasoline, a high-pressure heating means including a reaction chamber, means for feeding condensate heavier than gasoline from said fractionating condenser to said high-pressure heating means, means for conveying vapors from said reaction chamber to said fractionating condenser, means for passing unvaporized stock from said reaction chamber to said low-pressure heating means, means for withdrawing gasoline, means for withdrawing a manufactured unvaporized product, and means for supplying fresh charging stock to the apparatus.

4. The process of cracking hydrocarbon oils to produce gasoline comprising heating the hydrocarbon oils under low pressure conditions, fractionally condensing the vapors produced by said heating, withdrawing a condensed intermediate product he'avier than gasoline from the fractional condensing stage, heating and cracking'said intermediate product under high-pressure conditions, condensing the vapors produced by the high-pressure heating, passing unvaporized stock from the high-pressure heating to the starting point Where low pressure heating again occurs, and continuously withdrawing unvolatilized liquid oil from the lower pressure cracking means and uniting it with said condensed intermediate product which is passing to said high-pressure cracking stage.

5. The process of cracking hydrocarbon oils to produce gasoline comprising heating the hydrocarbon oils under low pressure conditions, fractionally condensing the vapors produced by said heating, withdrawing fractions heavier than gasoline, heating and cracking said fractions under high-pressure conditions, condensing the vapors produced by the high-pressure heating, passing unvaporized stock from the high-pressure heating to the starting point where low-pressure heating `again occurs, continuously withdrawing unvolatilized liquid oil from the lower pressure cracking stage, and passing said oil to the high-pressure cracking stage.

G. The process of cracking hydrocarbon oils to produce gasoline comprising primarily heating the hydrocarbon oils under superatmospheric pressure, fractionally condensing the vapors produced by said first heating, withdrawing a condensed intermediate product heavier than gasoline from the fractional condensing stage, heating and cracking said intermediate product in a second zone, condensing the vapors produced by said second heating, passing unvaporized stock from the second heating to thehstarting point where the first heating again occurs, and continuously withdrawing unvolatilized liquid oil from the `first cracking stage and uniting it lvith,

said condensedintermediate product which is passing to said second cracking stage.

7. Apparatus for cracking hydrocarbon oilscomprisinga low-pressure still, a highpressure still, means individualto each still for separating vapors i from unvaporized stock, means for fractionally condensing oil vapors from said stills, means for withdrawing a condensed intermediate product heavier than gasoline from the fractionalcondensing means, means forpassing unvaporized stock from the high-pressure still to the low-pressurestill, means for continuously withdrawing y unvolatilized liquid oil Vfrom the '-loW- pressure still and for uniting it with said iiitei-mediate product, and means lfor pumping said mixture to the high-pressure still. i

8. Apparatus for .cracking hydrocarbon oils comprising a low-pressure still,*a highpressure still, means individual. to each still for separating vapors from unvaporized stock, means for fractionally condensing oil vapors froml said stills, means for withdrawing a condensed intermediate product heavier than gasoline from the fractional condensing means, means for passing iinvaporized stock from the high-pressure stil-l to the low-pressure still, and means for passing unvolatilized oil from the low-pressure still to the high-pressure still.

9. The process of treating hydrocarbons as described in claim 4 characterized by continually adding fresh hydrocarbons to maintain a predetermined amount of liquid throughout the system, continually removing a portion of the unvaporized hydrocarbons from the system, and continually removing gasoline from the system.

10. The process of treating hydrocarbons as described in claim 5 characterized by continually adding fresh hydrocarbons to maintain a predetermined amount of liquid throughoutf the system, continually removing a portion f the unvaporized hydrocarbons from the system, and continually removing gasoline from' the system.

11. The process of cracking hydrocarbon oils which consists in heating and cracking an oil stock heavier than kerosene, separating vaporized products therefrom in a separating zone, partially condensing the vaporized products to produce a condensate heavier than gasoline and lighter than the feed stock and including substantial amounts of kerosene constituents, heating and cracking a substantial portion of the condensato in a separate operation under conditions of temperature and pressure suitable for cracking kerosene constituents,,separating vaporized inaterial therefrom in a second separating zone, and returning nnvaporized residual material lio 4 1,ss2,1oo

heavier than the condensate and lighter than the original oil stock from the second. sepa- `ating' zone to the rst cracking operation.

12. The process of cracking hydrocarbon 5 oils which consists in subjecting said oils t0 cracking conditions in a low-pressure zone, separating vaporized products therefrom, partially condensing` said vaporized products, subjecting said condensate together With unvaporized oil continuously Withdrawn from the low-pressure cracking 0peration to. cracking conditions in a separate operation in a hi gli-pressure zone, and returning un 'aporized residue from the high-pressure zone to the low-pressure zone.

13. The process of cracking hydrocarbon oils which consists in circulating said oil through a low-pressure heating and cracking zone. withdrawing vapors formed therein, partiallyY condensing said vapors, subjectingr the condensate together with oil unvaporized in said zone to cracking conditions in a separate zone operating at a higher pressure than the first zone, separately removing vapors from the residue in said separate zone, and returning unvaporized residue froml the separate zone to the irst zone.

HOMER T. DARLINGTON. 

